The Internet of Things refers to a network in which information about the physical world is obtained by deploying devices having particular sense, computation, execution, and communication capabilities, and information transmission, collaboration, and processing are implemented by using a network, so as to implement interconnection between a human and a thing and between one thing and another thing. An Internet of Things technology may be applied to fields such as a smart grid, intelligent agriculture, intelligent transportation, and environment detection.
A machine-to-machine (M2M) communications technology is used to bear an Internet of Things application on a mobile communications network. A device that performs M2M communication is referred to as a machine type communication (MTC) device. Some Internet of Things applications, for example, a smart meter, have relatively strict requirements on costs and power consumption of the MTC device.
At present, a low-cost MTC research project conducted by a standards organization—the 3rd Generation Partnership Project is devoted to reducing costs and power consumption of MTC terminals, and enhancing coverage of a network with respect to MTC terminals in some special environments (for example, a basement).
A feasible solution is to relay by using a terminal. As shown in FIG. 1, a terminal A implements relay between a terminal 1 and a base station and between a terminal 2 and the base station, a terminal B implements relay between a terminal 3 and the base station and between a terminal 4 and the base station, and the terminal B and a terminal C implement relay between a terminal 5 and the base station. Herein, the terminal A, the terminal B, and the terminal C are terminals that provide a relay service, and the terminal 1, the terminal 2, the terminal 3, the terminal 4, and the terminal 5 are terminals to which another terminal provides the relay service. The relaying by using a terminal can effectively reduce power consumption of a terminal and enhance coverage of a network with respect to a terminal in a special environment, and does not increase network complexity as a method in which a dedicated relay device or small cell is used does.
For ease of description, in this application, a terminal that provides the relay service is referred to as a “first terminal”, and a terminal to which another terminal provides the relay service is referred to as a “second terminal”.
In the foregoing terminal relay scenario, there is not a solution for paging the second terminal yet, nor a solution for updating area information of the second terminal.